What is the best practice for caring for herpes zoster (shingles) blisters?

Best Practice for Caring for Shingles Blisters

Keep intact blisters completely undisturbed, but if drainage is necessary, pierce at the base with a sterile needle while leaving the blister roof in place as a natural biological dressing, then apply bland emollient and maintain vigilant infection surveillance. 1, 2

Immediate Blister Management

For Intact Blisters

• Leave asymptomatic intact blisters completely alone and observe them without intervention. 2
• If the blister requires drainage due to size or discomfort, gently cleanse with antimicrobial solution first, taking care not to rupture it prematurely. 1, 2
• Pierce the blister at its base using a sterile needle with the bevel facing upward, selecting a site where gravity will facilitate drainage and discourage refilling. 1, 2
• Apply gentle pressure with sterile gauze swabs to facilitate complete drainage and absorb fluid. 1, 2

Critical Technique Points

• Never deroof or remove the blister roof—it must remain in place as it serves as a protective biological dressing that promotes healing. 1, 2, 3
• For large blisters that don't drain adequately, use a larger gauge needle and pierce multiple times if necessary. 1
• Many patients experience significant pain or burning during blister care; offer analgesia 30-60 minutes prior to any procedure. 1, 2

Wound Care and Barrier Support

• After drainage, gently cleanse again with antimicrobial solution. 1, 2
• Apply a bland emollient such as 50% white soft paraffin and 50% liquid paraffin to all affected areas to support barrier function, reduce transcutaneous water loss, and encourage re-epithelialization. 1, 2
• Apply a non-adherent dressing only if needed for protection or to absorb exudate. 1, 3
• Change all dressings using strict aseptic technique to prevent secondary infection. 1, 2, 3

Infection Prevention and Detection

Infection and sepsis represent significant risks and are major causes of mortality in patients with extensive vesicular eruptions, making vigilant surveillance essential. 1

• Perform daily washing with antibacterial products (such as chlorhexidine or zinc pyrithione) to decrease bacterial colonization. 1
• Obtain bacterial and viral swabs from any erosions showing clinical signs of infection (increased erythema, purulent drainage, warmth, or expanding borders). 1, 3
• Do not apply topical antimicrobials prophylactically—reserve them only for short periods when clinical infection is present. 1, 2
• Use systemic antibiotics if local or systemic signs of infection develop, following local antibiogram guidance for agent selection. 1

Antiviral Therapy

While the question focuses on blister care, it's critical to note that high-dose IV acyclovir remains the treatment of choice for varicella-zoster virus infections in immunocompromised hosts. 1

• For immunocompetent patients, oral valacyclovir 1 gram three times daily for 7 days or famciclovir 500 mg three times daily for 7 days should be initiated within 72 hours of rash onset. 4, 5, 6, 7
• Without adequate antiviral treatment, immunocompromised patients may develop chronic ulcerations with persistent viral replication complicated by secondary bacterial and fungal superinfections. 1

Monitoring and Documentation

• Document daily on a blister chart the number, size, and location of new blisters to track disease progression. 1, 2, 3
• Reassess within 24-48 hours if managed as an outpatient to ensure appropriate response to treatment. 2, 3
• In immunocompromised hosts, skin lesions may continue to develop over 7-14 days and heal more slowly than in healthy hosts (who typically heal within 2 weeks). 1

Common Pitfalls to Avoid

• Never deroof blisters—this is the single most important technical error to avoid, as the blister roof provides essential protection. 1, 2, 3
• Do not use topical antimicrobials routinely or prophylactically; this promotes resistance without proven benefit. 1, 2
• Do not delay antiviral therapy beyond 72 hours of rash onset, as efficacy diminishes significantly. 6, 8, 7
• Avoid inadequate pain control—acute zoster pain requires appropriately dosed analgesics, often combined with neuroactive agents like amitriptyline. 8